In currently-available lithium ion batteries, an organic electrolyte solution is mainly used as an electrolyte. However, although the organic electrolyte solution shows a high ionic conductivity, since the electrolyte solution is a flammable liquid, there is a concern of occurrence of leakage, ignition or the like when used in a battery. Taking such concern into consideration, development of a solid electrolyte having a higher degree of safety is expected as an electrolyte for a next-generation lithium ion battery.
In order to solve the problem, a method for producing an all-solid lithium battery produced by using a sulfide-based solid electrolyte comprising a sulfur atom, a lithium atom and a phosphorous atom as main components has been developed (Patent Document 1).
The method for producing an all-solid lithium battery disclosed in Patent Document 1 has a defect that it is not suited to mass production since production is conducted by putting electrolyte particles in a mold, followed by pressure application.
In order to solve the subject, a technology has been studied in which a slurry obtained by mixing electrolyte particles and a binder is applied to form an electrolyte layer. In this technology, normally, a positive electrode layer or a negative electrode layer is produced by a coating method, an electrolyte layer is formed on the positive electrode layer or the negative electrode layer by a coating method, and further, a positive electrode layer or a negative electrode layer on the electrolyte layer. However, this technology has a defect that it is difficult to form by coating the electrolyte layer on the electrodes that are produced by a coating method.